title: Streptavidin-aequorin fusion protein for bioluminescent immunoassay.
abstract: The fusion protein of streptavidin to aequorin (STA-AQ) was highly purified from inclusion bodies in Escherichia coli cells and applied to a bioluminescent sandwich immunoassay. α-Fetoprotein (AFP), which is a serological marker of liver cancer, was used as a model analyte to test STA-AQ in an immunoassay. The measurable range of AFP by the sandwich immunoassay, using the complex of STA-AQ and the biotinylated anti-AFP antibody, was 0.02-200 ng/mL with an average coefficient of variation of 4.9%. The detection sensitivity with the complex of STA-AQ and the biotinylated anti-AFP antibody was similar to that with the complex of biotinylated aequorin, streptavidin and the biotinylated anti-AFP antibody. STA-AQ would be a useful reporter protein for immunoassays.
authors.affiliation: Yokohama Research Center, Chisso Corporation, Yokohama, Japan. sinouye@chisso.co.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Inouye
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Sato
authors.forename: Satoko
authors.initials: S
authors.lastname: Sasaki
authors.forename: Yuiko
authors.initials: Y
authors.lastname: Sahara
mesh_terms: D000331:Aequorin / Q000235:genetics / Q000378:metabolism*; D000906:Antibodies / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000276:immunology; D019921:Biotinylation; D002118:Calcium / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli; D015870:Gene Expression; D006801:Humans; D007118:Immunoassay; D008027:Light; D057230:Limit of Detection; D008113:Liver Neoplasms / Q000175:diagnosis; D008163:Luminescent Measurements; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D019809:Streptavidin / Q000235:genetics / Q000378:metabolism*; D013302:Streptomyces / Q000235:genetics / Q000378:metabolism; D000509:alpha-Fetoproteins / Q000032:analysis* / Q000276:immunology
chemical_list: D000906:Antibodies; D014408:Biomarkers, Tumor; D011993:Recombinant Fusion Proteins; D000509:alpha-Fetoproteins; D000331:Aequorin; D019809:Streptavidin; D002118:Calcium